(create-constraints

 ((order-goals)
  :goal-conditions ((on ?x ?y)
		    (on ?y ?z))
  :belief-conditions ((not (on ?y ?z)))
  :delete (on ?x ?y))

 ((clear-block)
  :goal-conditions ((on ?x ?y))
  :belief-conditions ((not (on ?x ?y))
		      (on ?w ?x))
  :add (not (on ?w ?x)))
)